Bladeless pump impeller



Oct. 20, 1953 F. l. LINDAU ETAL 2,655,868

BLADELESS PUMP IMPELLER Filed Sept. 8, 1947 2 Sheets-Sheet 1 INVENTORS FRED I. LINDAU ROBINSON C. GLAZEBROOK ATTORNEY Oct. 20, 1953 F. l. LINDAU ET AL 2,655,868

BLADELESS PUMP IMPELLER Filed Sept. 8, 1947 2 Sheets-Sheet 2 FIG. 5 35 FIG. 7 36 30 v a INVENTORS FRED l. LINDAU ROBINSON C. GLAZEBROOK 39 26 $62 la v4 ATTORNEY Patented Oct. 20, 1953 UNITED STATES PATENT OFFICE br'ook, Turtle Ridge, Wis., assignors to Fairbanks, Morse & 00., Chicago, 111., a corporation of Illinois Application September 8, 1947, Serial No. 772,610

3 Claims. (Cl. 103-103) This invention relates to impellers for centrifugal pumps, and has particular reference to a centrifugal pump impeller of a novel bladeless, non-clogging character, suitable especially for use in pumping fluids such as sewage, containing stringy, pulpy and solid matter. The presently improved impeller however, is not limited to sewage pumps, as it may be readily embodied in centrifugal pumps having wide utility in the pumping of fluids generally.

In sewage systems employing prevailing or conventional centrifugal pumps such as those of bladed impeller types and the like, it is a common practice inorder to minimize pump clogging, to use pumps of appreciably larger capacity than is otherwise necessary, to facilitate the pump passage of solids and stringy matter. The larger capacity pumps require of course, correspondingly large operating motors, which thus increases initial costs of installations. Moreover, because of pump capacities above the optimum requirements, in many instances the pumps are operated only intermittently, whereas continuous operation is far preferable particularly in processes of bacteriological purification of sewage.

The consequence then is a sacrifice of sewage.

purification efficiency for a reduction in the frequency of pump clogging. But even with oversize pumps, impeller clogging while of less frequency than attends the use of smaller pumps,

occurs so often in many if not most installations,

as to constitute a serious problem.

The foregoing is applicable in general, to many types of pumping systems other than sewage systems. Moreover, in instances of pumping systems utilized to convey or transfer food material,

Other objects and advantages of the invention will appear readily from the following descripthe section being taken along line |--I in Fig. 2;

Fig. 2 is an axial sectional view of the pump, illustrating in part the improved character of impeller now provided;

Fig. 3 illustrates the improved impeller in an enlarged end view thereof, with the impeller passage shown in phantom lines; 7

Figs. 4, 5, 6 and 7 are axial sections of the impeller as taken respectively, along lines 4'4,

, 55, 66 and 1-4 in Fig. 3, and

Fig. 8 is a view in perspective, of a core utilized in casting-in the impeller passage in impeller formation, the core here being shown as an aid in illustrating the trend of the passage.

Referring first to Figs. 1 and 2, there is illustrated a centrifugal pump embodying an impeller constructed according to the present invention.

The pump shown, include a casing providing a central casing section 10 having an impeller chamber ll terminating in a tangential discharge passage I2 (Fig. 1). The central casing section is closed at its opposite sides by casing closures l4 and I5, the closure I4 affording an axial inlet port I6 through which fluid is adconsequent to impeller blade damage to such material.

Accordingly, the principal object of the present invention is to provide an improved centrifugal pump impeller which will obviate the foregoing disadvantages by affording a pump which may be utilized in sewage and other pumping systems, in sizes appreciably smaller than those now used in a given system, and which may be sharp turns and projections outstanding therein.

mitted to the pump. The opposite closure l5 provides a bearing and stuffing box assembly l8 for the pump impeller drive shaft I9, the latter operatively supporting the impeller 20 within the casing. Shaft l9 may be driven by an electric motor or other power means (not shown). As indicated in Fig. 2, the impeller has an axial suction eye 22 in register with the casing port It, and a fluid passage shown in part only, at 23 and 24, leading to and opening in the impeller periphery, as will presently more fully appear.

The character and structural formation of the presently improved impeller 20, appear from the views of Figs. 3 through 7. As there shown, the

' impeller comprises a body 25 preferably although not necessarily, of a one-piece or unitary construction, providing a section 27 of circular pe- 0 1) of the impeller drive shaft l9.

Within the impeller body 26 is a single passage 3 35 in open communication with the impeller suction eye 22 provided in the small end 36 of the body section 28, the suction eye being of any desired shape, preferably circular as shown, and having its center coincident with the axis of the impeller. The passage 35 in the portion thereof Within the body 26, is characterized in the present example, by a circular cross-section of a given diameter, obtaining substantially uniformly throughout the passage.

be understood that the passage may have other than a circular section, as an elliptical or hexagperiphery of the latter.

As the passage approaches the periphery of the body section 27, it opens to the periphery While the circular. sectioned passage is presently preferred, it is to into and initially as indicated at 38 in Fig. 6, and thence continues along the periphery of the impeller until the bottom surface 39 of the passage merges into the impeller peripheral surface at 40 (Fig. 1). As a result, the portion of the passage open to the impeller periphery, defines a channel 42 of gradually decreasing depth, such as is indicated in Figs. 1 and 3.

The character of the passage core and mold which may be utilized in forming the inlet eye 22, passage 35 and its outlet channel 42, and the impeller body portion 21, is illustrated in Fig. 8. The helical trend of the passage 35 is there clearly shown, and as appears in this figurethe helical extent of the passage including the channel portion thereof, is substantially more than a single helical turn, although it is to be understood that the helical length thereof may be more or less than one turn, as desired.

The impeller may be balanced in any suitable or well-known manner. For example and as indicated in the views of Figs. 4 through 7, in forming or casting the impeller, it may be relieved or cored out in determined zones thereof, as appears at 45 in the several figures referred to.

From the foregoing, it will be now fully appreciated that the presently improved impeller is of blade-less character and affords a single passage between the suction eye and the impeller periphery, wherein the passage is smoothly helical in trend through the impeller, thus devoid of sharp turns and projections in any Zone or zones of the passage. In effect, passage 35 is a continuation of the suction eye 22. Accordingly, stringy matter and solids up to a size approximating the diameter of the impeller passage, will pass through the impeller without stoppage or clogging.

Therefore, centrifugal pumps embodying impellers of the presently improved character, are particularly suitable for use as trash or process pumps, and may be utilized to great advantage in sewage systems and the like. Such pumps may be provided in smaller sizes than heretofore required for reasons hereinbefore stated, and. operated continuously over long periods, thereby effecting substantial savings in installation and operating costs, and affording when embodied in sewage purification systems, an improvement in the effectiveness of such systems as a consequence of continuous pump operation. Further since the presently improved impeller provides a continuous passage devoid of shoulders and projections, pumps embodying impellers of the character now described, are particularly suitable for use in food handling and processing systems generally, as before indicated. Food material, fish and the like, will pass through the impeller without bruising or damage, thereby eliminating the damage heretofore encountered in installations employing bladed impeller pumps.

Having described and illustrated a presently preferred embodiment of the invention, all modiflcations as come within the spirit and scope of the appended claims, are contemplated.

We claim:

1. A rotor for centrifugal pumps, comprising a unitary rotor body having a circular periphery and a single helical passage having its inlet end opening axially of the body at one side, said passage extending entirely within the body through at least one helical turn and having its discharge end inwardly adjacent the periphery of the body, said body further providing a discharge channel in communication with the discharge end of said passage and extending in the periphery of the body throughout substantially the entire circular extent thereof, with the channel depth gradually decreasing to mergence with the periphery of the body, and said channel being positioned in the periphery of the body such that the longitudinal axis of the channel lies in a plane normal to the axis of the rotor.

2. In a centrifugal pump, the combination with a pump casing assembly providing a circular impeller chamber, a discharge passage extending tangentially from the chamber, and an inlet opening axially in one side of the casing assembly, of a centrifugal impeller rotatable in the casing assembly, said impeller comprising a unitary body having a circular periphery and a single tubular passage opening axially of the body at one side and in alignment with the casing inlet, said passage being entirely within the body and extending helically therein through substantially one helical turn and terminating in a discharge opening inwardly adjacent the circular periphery of the body, said body further providing a discharge distribution channel communicating with said passage discharge opening and extending in said periphery of the body throughout substantially the entire circular extent thereof, the channel depth gradually decreasing to substantial mergence with said periphery of the body, and said discharge distribution channel being positioned in the periphery of the said body such that the longitudinal axis of the channel lies in a plane normal to the axis of the body.

3. In a centrifugal pump, the combination with a pump casing of volute form providing an axial inlet at one side of the casing and a tangential discharge outlet at the casing periphery, of a unitary impeller rotatable in the volute casing, the impeller comprising an impeller body having a circular periphery and providing a single tubular passage opening axially of the body at one side and in alignment with said axial inlet of the volute casing, the tubular passage extending helically in the body through substantially one helical turn and terminating in a discharge outlet inwardly of the body adjacent the circular periphery thereof, said tubular helical passage being of uniform diameter throughout its length and constitutin the sole displacement producing means of the impeller, and said body further having a discharge distribution channel open to said circular periphery of the body, extending from said discharge outlet of the helical passage throughout substantially the entire circular extent of the body periphery in decreasing depth to mergence with said periphery of the body, said channel being positioned in the body periphery such that its longitudinal axis lies in a plane normal to the rotary axis of the impeller body.

FRED I. LINDAU.

ROBINSON C. GLAZEBROOK.

6 References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Breuer Sept. 23, 1913 Hazell Oct. 16, 1923 Fabrin Apr. 15, 1930 Sperry Dec. 29, 1931 Wood Mar. 15, 1932 FOREIGN PATENTS Country'- Date Germany Nov. 26, 1941 

